Piston water-meter



(No Model.)

G. H. FOX.

PISTON WATER METER.

No. 327,671. Patented Oct. 6, 1885.

N. nana men-mman@ washing. 0.a

Unitarian Srnrns GEORGE HENRY F OX, OF BOSTON, MASSACHUSETTS.

PISTN WATER-itil ETER.

.g part of Letters Patent No. 327,671, dated October 6, 1885.

Application died January 3, 1855. Serial No. 151,805. (No model.)

To @ZZ whom it may concern:

Be it known that I, Geenen HENRY FOX, a citizen oi' the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and uset'ul Improvements in Fluid-Meters; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying draw` ings, and to letters or iigures oi' reference marked thereon, which ii'orm a part of this specification.

rlhis invention relates to fluid-meters7 so called, and especially to that class in which a pair ot' pistons are employed and operated by cranks and connecting-rods so arranged with respect to each other as to overcome any tendency to a dead-center, and thereby prevent stoppage.

My present invention may be considered as an improvement upon, and relates to, an application for Letters Patent on meters eXecuted by myself on the 18th day of December, 188i.

The drawings accompanying this specification represent, in Figure l, a vertical central longitudinal section of a meter embodying my improvements, while Figs. 2 and 3 show modiications of the same improvements.

Since this meter in general construction is similar to that shown in my previous application, will describe it very brictiy.

In these drawings, A represents the shell or outside casing ot a meter provided with a cap, B.

Centrally of the shell and dividing it into two similar equal and corresponding chambers, G D, is the partition E, in which rotates a shaft, a, to which is attached the connecting-rods I) c and cranks ef.

The valves are shown at F G as ordinary slide-valves,aml cooperate with ducts g g h h, whichalternately act as discharge and inlet passages, while common discharge-passages it" lead to the general discharge Vor outlet orifice.

rlhe water to be measured is introduced through the main inlet-port into the valvechamber, and is thence conducted by means,

of the valves through the inletpassages upon either side of the two pistons,dependcnt upon circumstances and the position of parts at the time.

Attached to the upper part vof the rotary shaft c is the registering-dial, so arranged and adjusted as to record each entire revolution of said shaft, which represents double the capacit-y of the two chambers C D.

Hitherto in meters of this class an almost insuperable objection has existed in overcoming the positive movement ot` the cranks and their connecting-rods with their operative pistous during the short interval or space of time when the valve is changing its direction in movement or the reversal oli its stroke. During that time both passages then acting as inlet and outlet ports are closed, and the liquid is held confined without any means of inlet or exhaust. This position ofthe valve prevents the movement ot' the piston in this chamber, owing to the non-elasticity of water. Furthermore,during this interval of time the opposite piston and crank are traveling in unison with the crank and connecting-rod attached to the piston in thc measuring-chamber, which is closed bythe valve, and thus all of the various parts connecting the two pistons are subjected to great strain, and some one of the parts is liable to be so bent and twisted as toai't'ect the efticiency of the machine, or else break and render the apparatus useless for the time, u1;- til repairs may be made.

The object ol my invention is to overcome the above serious objections now existing in meters of this class; and for this purpose I propose to loosely attach the pistons H I to their respective connecting-rods b c, whereby, when one piston is prevented from movement by the position oi" the valve in reversing its motion, still the connecting rod is perfectly free to advance to its extreme throw, which it usually attains j ust at that very moment. Thus in Fig. l l have constructed and cast cylindrical projections j j upon the outside of the heads ot' the pistons of a diameter slightly larger than the hole through which the con` necting-rods pass, in order to retain the piston in proper position thereon. Vlithin said abutinents are inserted disks it 7d, which are connected to the ends of said rods b c. Furthermore, the length of said chamber extends beyond the extreme point ever reached by the ICO disks k 7c upon the connecting-rods consequent upon the throw of the cranks ef. Screw-caps Z Z', mounted upon the ends of said projections, close communication between opposite sides of the pistons.

In Figs. 2 and 3 I have shown slight modications of methods whereby the piston may be loosely attached to the connecting-rods. In the former drawing I have constructed a central hub to form a bearing and afford suitable support to the connecting-rod, which isprovided with a iiXed shoulder, m, and adjustable nut n, the distance between the two forming a bearing longer than theYjournal-surface fm of the piston; hence the rod is free to advance wit-hout affecting the position of the piston, which remains stationary. In the latter iigure I have represented a vertical pivot, at p, to which is attached the end of the connect-ingrod. The latter is slotted at a sufficiently to overcoinethe slight advance movement of said rod at the time the piston has stopped and the crank has attained its eXtreme throw, and thus obviatc and overcome strains or thrusts which otherwise would occur.

rIhe operation within the meter of my improvements is as follows: It being understood that piston I has just reached that position in which its valve G has closed both the passages h h, prior to a change in its movement or re- Versal of the stroke; hence there is no communication from or into' said chamber D, and the liquid, which is now upon both sides of the piston I, is confined. During this interval the crankf must still advance a short distance with its connecting-rod c in order to pass the center or the position of axial alignment ot' said two parts, at the same moment piston H in the chamber Gis advancing in the direction of arrow I, and since the two cranks are connected to the same shaft a, there is a tendency for said piston H to carry the other one, I, by the center. Herein arises the difficulty, since the valve G, co-operating with the latter pistou, has completely closed the chamber, 'and the non-elasticity of' the water prevents any change in the position of said pis ton therein, and consequently some of the cooperative parts must yield or break, unless, While said piston remains stationary, the crank and connectingrod are permitted to advance.

The construction and arrangement of the pistons loosely upon their connecting-rods obviates this, and the moment the valve G has closed the passages .7L h the piston I stops, while the rod c advances slightly at the critical moment. rIhe crank f', to which it is at tached, has .then reached its-eXtreme stroke and now begins to retreat. Immediately there upon the valve has moved sufficiently to open its ports, and supply-liquid now commences toenter between the head of the meter and the piston. This ilow of water with its attendant pressure then moves the piston back again until the latter abnts against the end of 65 the connecting-rod. Thus, when said'piston reaches a similar position to that above described at the opposite end of the stroke, the rod is again free to advance the slight distance required beyond where the piston stops in order to pass the center, and thus prevents any pressure being brought against said piston which would wrench, distort, or perhaps break some one of the operative parts.

I do not desire to be limited to the precise construction herein shown, since there are many mechanical expedient-s which may be resorted to in order to accomplish the same result. One very simple equivalent would be `to make the pistou fast to the connecting-rod while the latter is capable of slip upon the crank. i

Now, to sum up, I consider the gist of my invention consists in the. compensating slip movement between the crank and piston, whereby the latter may remain stationary for a short interval of time, while its valve has closed both ports, and the crank in reaching its center is i'ree to move its proper distance without affecting the position of the piston.

Vhat I desire to claim and secure by Leters Patent of the United States is-v Y l. In a crank water-meter, a piston loosely secured to the connecting rod, whereby the latter and its operating-crank are permitted to move onward while the piston remains at rest just prior to the completion of a stroke, substantially as and for the purpose stated.

2. The combination,with a rotary shaft provided with a crank and its connecting-rod, of roo a reciprocating piston loosely attached tothe extremity of the latter, whereby at certain stated times the crank and rod may move while the piston remains stationary, substantia ly as stated.

In testimony whereof I affix my signature in vp resence of two witnesses.

GEORGE HENRY FOX.

Vitnesses:

H. E. LODGE, A. F. IIAYDEN. 

